In a closed refrigerant circuit of this type, a compressor, a condenser and an expansion member are connected in addition to the evaporator. During air conditioning operation, the vaporous refrigerant which comes from the evaporator is compressed in the compressor and is conducted into the condenser. The condenser can be arranged by way of example in the front end of the vehicle and can be flowed through by the air stream, as a result of which the refrigerant which is situated in the condenser condenses into its liquid phase, to be precise with the dissipation of thermal energy to the air stream which is flowing through. The refrigerant which is then liquid is expanded in the downstream expansion member to form a two-phase liquid/vapour mixture which is fed to a separator. A phase separation takes place in the separator, in the case of which phase separation the liquid phase is separated from the vapour phase of the refrigerant. The vapour phase is conducted via a bypass line directly to the evaporator outlet. The liquid phase which is separated from the vapour phase is conducted through the heat exchanger tubes of the evaporator. During air conditioning operation, the evaporator (for example, a cross-counterflow heat exchanger) is flowed through by way of an air flow to be cooled which is guided into the vehicle interior compartment. The refrigerant liquid phase in the evaporator is therefore evaporated into the vapour phase with absorption of thermal energy from the air flow, while the air flow is cooled at the same time.
WO 2015/073106 A1 has disclosed an evaporator of the generic type which has a bottom-side inlet chamber which is connected in flow terms via evaporator tubes to an evaporator outlet side. A separator for a phase separation is integrated into the evaporator inlet chamber. The evaporator tubes are realised in each case as a flat tube with a plurality of micro-channels, through which the refrigerant is guided.
In WO 2015/073106 A1, the phase separation takes place in the separator by way of the use of centrifugal force. To this end, the two-phase liquid/vapour mixture is introduced into the evaporator inlet chamber in a vortex flow along the inner wall of a distributor tube. As a result, the vapour phase collects radially within the vortex flow, and the said vapour phase is fed to a bypass line. In contrast, the liquid phase collects radially on the outside at the vortex flow which is guided along the distributor tube inner wall. The use of centrifugal force is complicated in terms of process technology. In addition, a structurally complicated separator geometry is required.
U.S. Pat. No. 7,832,231B2 has disclosed an evaporator, the evaporator tubes of which are likewise realised as flat tubes with micro-channels. The evaporator has an upper-side (in the evaporator height direction) inlet chamber, into which a separator for a phase separation is integrated. EP 2 159 514 A2 has disclosed an evaporator, the evaporator tubes of which are likewise configured as flat tubes, into which in each case a plurality of micro-channels are integrated. Further evaporators are known from WO 2006/083442 A2 and from US 2015/0345843 A1.